Methods and systems for a dual wind gradient coil

Abstract

Methods and systems are provided for a gradient coil assembly. In one embodiment, a gradient coil assembly comprises a hollow, first gradient coil and a solid, second gradient coil co-wound with the first gradient coil. In this way, the turn density of the gradient coil assembly may be increased.

The invention claimed is: 
     
       1. A gradient coil assembly, comprising:
 a hollow, first gradient coil; and 
 a solid, second gradient coil co-wound with the first gradient coil, the first gradient coil co-planar with the second gradient coil. 
 
     
     
       2. The gradient coil assembly of  claim 1 , wherein the first and second gradient coils are coupled in series, and wherein the first gradient coil being co-planar with the second gradient coil comprises, at any point along the gradient coil assembly, the first gradient coil and the second gradient coil being located on a same plane at that point. 
     
     
       3. The gradient coil assembly of  claim 1 , wherein the first and second gradient coils are each configured to couple to a gradient amplifier/controller configured to supply current to the first and second gradient coils, and wherein the first gradient coil being co-wound with the second gradient coil includes the gradient coil assembly having alternating loops of the first gradient coil and the second gradient coil. 
     
     
       4. The gradient coil assembly of  claim 1 , wherein the first gradient coil is configured to couple to a cooling system configured to supply a coolant flow through the first gradient coil. 
     
     
       5. The gradient coil assembly of  claim 1 , wherein the first gradient coil and second gradient coil are each in face-sharing contact with an insulating layer along a length of each of the first and second gradient coils. 
     
     
       6. The gradient coil assembly of  claim 1 , wherein all loops of the first gradient coil are coupled to a surface and all loops of the second gradient coil are coupled to the surface, and wherein the surface is a cylindrical surface. 
     
     
       7. The gradient coil assembly of  claim 1 , wherein the first gradient coil has a first cross-sectional area, and wherein the second gradient coil has a second, smaller cross-sectional area, wherein all loops of the first gradient coil are coupled to a surface and all loops of the second gradient coil are coupled to the surface, and wherein the surface is a flat surface such that all loops of the first gradient coil and all loops of the second gradient coil are located on a same plane. 
     
     
       8. The gradient coil assembly of  claim 7 , wherein the first gradient coil comprises a solid portion surrounding a hollow conduit, and wherein a portion of the first cross-sectional area that is comprised of the solid portion of the first gradient coil corresponds to a third cross-sectional area that is equal to the second cross-sectional area. 
     
     
       9. The gradient coil assembly of  claim 1 , wherein one or more of the first and second gradient coils is insulated. 
     
     
       10. A Magnetic Resonance Imaging (MRI) system comprising:
 a gradient coil assembly disposed cylindrically around an imaging volume, the gradient coil assembly including a first gradient coil co-wound with a solid, second gradient coil, the first gradient coil having a central conduit, and the first gradient coil and the second gradient coil collectively forming a series of continuous concentric loops; 
 a gradient amplifier/controller coupled to the gradient coil assembly and configured to deliver pulse sequences to the gradient coil assembly; and 
 a cooling system coupled to the gradient coil assembly and configured to deliver coolant to the central conduit of the first gradient coil. 
 
     
     
       11. The MRI system of  claim 10 , further comprising a main magnet and a radiofrequency (RF) coil, and wherein the series of concentric loops comprises a first loop of the co-wound first gradient coil and second gradient coil, a second loop of the co-wound first gradient coil and second gradient coil, and a third loop of the co-wound first gradient coil and second gradient coil, the third loop concentric with the second loop and the second loop concentric with the first loop, and wherein, along a first axis of the gradient coil assembly, the second loop is located intermediate the first loop and the third loop. 
     
     
       12. The MRI system of  claim 10 , further comprising a shielding coil disposed cylindrically around the imaging volume and adjacent the gradient coil assembly, and wherein the gradient coil assembly includes a surface on which the first gradient coil and second gradient coil are mounted, and wherein the first gradient coil and the second gradient coil have equal vertical displacement relative to the surface at each point of gradient coil assembly along an entire length of each of the first gradient coil and second gradient coil. 
     
     
       13. The MRI system of  claim 10 , wherein the first gradient coil and the second gradient coil are each in face-sharing contact with an insulating layer along an entire length of each of the first gradient coil and the second gradient coil. 
     
     
       14. The MRI system of  claim 10 , wherein the first gradient coil is coated in an insulating material, and wherein the second gradient coil is in face-sharing contact with the insulating material, and wherein the insulating material comprises a polymer material. 
     
     
       15. A method, comprising:
 flowing current through a first gradient coil and a second gradient coil to generate a controlled magnetic gradient field along an axis of an imaging volume, the first gradient coil and the second gradient coil each in face-sharing contact with a common insulating material, the first gradient coil, the second gradient coil, and the insulating material all wound into a single series of continuous and concentric loops; and 
 flowing coolant through a conduit of the first gradient coil to cool the first gradient coil and the second gradient coil, the second gradient coil in thermal contact with the first gradient coil. 
 
     
     
       16. The method of  claim 15 , wherein flowing current through the first gradient coil and the second gradient coil comprises activating a gradient amplifier/controller to deliver pulse sequences to the first gradient coil and the second gradient coil. 
     
     
       17. The method of  claim 15 , wherein flowing current through the first gradient coil and the second gradient coil comprises flowing current through the first gradient coil and the second gradient coil in series. 
     
     
       18. The method of  claim 15 , wherein flowing coolant through the first gradient coil comprises pumping coolant from a cooling system to the conduit of the first gradient coil. 
     
     
       19. The method of  claim 15 , wherein the magnetic gradient field is generated along an x-axis of the imaging volume. 
     
     
       20. The method of  claim 15 , wherein the magnetic gradient field is generated along a y-axis of the imaging volume.